You could always try growing it in a large pot in a sheltered space. Then you can give it the perfect soil type. Looks like it’s quite a small tree so probably won’t mind too much. We have a sheltered terrace behind our gite/cottage where it doesn’t get frosty and that’s where I put some of our more tender trees / large bushes in big pots.
Also, bear in mind an occasional frosty night probably won’t be a problem and we are certainly finding in Lot-et-Garonne that our winters are milder.